Celebi, Demet; Celebi, Ozgur; Baser, Sumeyye; Ozcan, Halil; Taghızadehghalehjoughı, Ali; Hacimuftuoglu, Ahmet

Bidirectional communication between the gut microbiota and the brain has been increasingly recognized, with growing evidence suggesting its relevance in schizophrenia. Altered microbiota composition may contribute to gastrointestinal barrier disruption, immune activation, and metabolic dysfunction. Given the multifactorial etiology of schizophrenia involving genetic, epigenetic, and environmental factors, microbiota-related mechanisms may represent an important pathway in disease development. This prospective, controlled study investigated gut microbiota composition and systemic inflammatory markers in schizophrenia patients. Blood and stool samples were obtained from 14 patients with schizophrenia and 6 matched healthy controls. Microbiota profiles were determined through 16 S rRNA gene sequencing, while serum levels of Claudin-1, Occludin, E-cadherin, Zonulin, IL-1β, IL-6, and TNF-α were analyzed using ELISA. Firmicutes and Bacteroidota were the predominant phyla in both groups. However, alpha diversity (Shannon index, p < 0.05) and beta diversity (Permanova, p < 0.01) analyses showed significant differences between patients and controls. ELISA results demonstrated significantly elevated levels of IL-1β, IL-6, TNF-α, Claudin-1, and E-cadherin (all p < 0.05) in patients, whereas Occludin was significantly decreased (p < 0.05) and Zonulin levels were unexpectedly lower compared to controls. Results indicate significant gut dysbiosis and heightened systemic inflammation in schizophrenia patients. This interplay between microbial composition, intestinal permeability, and inflammatory processes may contribute to the pathophysiology of the disorder. Further studies with larger cohorts, including antipsychotic-naïve first-episode patients, are warranted to clarify causality and evaluate microbiota-targeted interventions as potential therapeutic strategies.

Acer, Ömer; Genç Bahçe, Yasemin; Özüdoğru, Osman

A third booster doses for the 2019 coronavirus disease (COVID-19) is widely used all over the world, especially in risky individuals, with the recommendation of WHO. The purpose of this study was to evaluate the effectiveness of mRNA (BNT162b2), and CoronaVac (Sinovac Biotech) vaccines as a reminder dose following two doses of CoronaVac against COVID-19 infection, serious illness, and mortality in the geriatric population aged 75 and older during the delta variant dominant period. Our study comprised 2730 individuals the age of 75 and older in total, of which 1082 (39.6%) were male and 1648 (60.4%) were female. The vaccine effectiveness (VE) of 2 doses of CoronaVac + 1 dose of BNT162b2 vaccine combination against COVID-19 was determined as 89.2% (95% Confidence interval (CI) 80.7–93.9%), while the VE of 3 doses of CoronaVac vaccine was determined as 80.4% (95% CI 60.5–90.2%). Geriatric patients who received three doses of CoronaVac vaccine did not need intensive care. No deaths were observed in the vaccinated groups. While the VE of vaccination with 2 doses of CoronaVac + 1 dose of BNT162b2 was 41.8% (95% CI 0–74.1%) against hospitalization, 64.4% (95% CI 0–94.7%) against intensive care unit admission, the VE of vaccination with three doses of the CoronaVac was 78.2% (95% CI 0–96.5%) against hospitalization. In conclusion, our research showed that, even with the emergence of viral variants, a third dose of the CoronaVac and BNT162b2 vaccines is highly effective against symptomatic SARS-CoV-2 infection. Third-dose vaccination regimens, including heterologous and homologous vaccines, can be an effective tool in controlling the COVID-19 pandemic and the emergence of new variants.

Genç Bahçe, Yasemin; Acer, Ömer; Özüdoğru, Osman

Older age (>60 years) has been identified as the main risk factor for COVID-19. In this study, we aimed to evaluate the efficacy of Pfizer–BioNTech and CoronaVac vaccines against COVID-19 infection, serious illness, and mortality in the geriatric population. We found that 2 doses of CoronaVac vaccine were ineffective in protecting against COVID-19 infection in people over 65 years of age, while the vaccine efficacy (VE) of the mRNA vaccine against COVID-19 was 80% (95% CI 70–87). The VE of full vaccination with BioNTech was 89% (95% CI 53–97) against hospitalization, 79% (95% CI 0–97) against death, and 79% (95% CI 0–97) against intensive care unit (ICU) admission. However, the VE of full vaccination with CoronaVac was 50% (95% CI 33–63) against hospitalization, 53% (95% CI 26–70) against ICU admission, and 56% (95% CI 30–73) against death. In conclusion, we found that the mRNA vaccine has higher efficacy against severe COVID-19 infection and mortality in the geriatric population than the inactivated vaccine. Booster doses of vaccines should be considered in increasing the effectiveness of inactivated vaccines. Given the potential of SARS-CoV-2 mutations evading vaccination protection and the risk of reduced immunity over time, regular monitoring of vaccine effectiveness in the real world is critical.